DISCLAIMER: PW's dosage information is gathered from users and resources for educational purposes only. It is not a recommendation and should be verified with other sources for accuracy.

Propylhexedrine (commonly known as Benzedrex and Obesin) is a synthetic stimulant and structural analog of methamphetamine that is widely used medicinally as a nasal decongestant (for relief of congestion due to colds, allergies and allergic rhinitis) and sometimes used recreationally as an over-the-counter "legal high".

In the United States, propylhexedrine is most commonly found in over-the-counter Benzedrex nasal inhalers. Benzedrex was first manufactured by Smith, Kline and French after the Benzedrine inhaler, which contained racemic amphetamine, became unavailable following the placement of amphetamines on the US Schedule II status (highest abuse potential, yet with accepted medicinal uses). Propylhexedrine has also seen use in Europe as an appetite suppressant under the trade name Obesin.

Chemistry

Propylhexedrine is structurally similar to phenylethylamine and its derivatives, with the only structural difference being the substitution of an alicyclic cyclohexyl group for the aromatic phenyl group of phenethylamine. It can be considered a structural analog of methamphetamine, with the main difference being that propylhexedrine has a saturated cyclohexane ring where methamphetamine has a benzene ring.

Moreover, propylhexedrine is a chiral compound (the α-carbon is chiral), and active ingredient contained in Benzedrex inhalers is racemic (RS)-propylhexedrine as the free base. (S)-Propylhexedrine, also known as levopropylhexedrine, is believed to be the more biologically active isomer of the two. (S)-Propylhexedrine can be synthesized from methamphetamine.

Pharmacology

Propylhexedrine affects the central nervous system (CNS) by acting as a releasing agent for monoamineneurotransmitters such as dopamine, norepinephrine, and serotonin by binding to and reversing their transporters, leading to the release of them into the synaptic cleft. The increased level of monoamines within the synapse is thought to result in increased activity at these receptors. Additionally, propylhexedrine appears to antagonize the VMAT2 transporter, leading to a further increase in the aforementioned monoamines.

The pharmacological actions of propylhexedrine are similar to that of structurally similar stimulant phenethylamines, such as amphetamine or methamphetamine, albeit in a generally less potent and recreationally desirable fashion.

Subjective effects

The effects listed below are based upon the subjective effects index and personal experiences of PsychonautWikicontributors. These effects should be taken with a grain of salt and will rarely (if ever) occur all at once, but heavier doses will increase the chances of inducing a full range of effects. Likewise, adverse effects become much more likely on higher doses and may include serious injury or death.

Physical effects

Stimulation - In terms of its effects on the physical energy levels of the user, propylhexedrine is usually considered to be extremely energetic and stimulating in a fashion that is extremely similar to that of amphetamine or methamphetamine, and stronger than that of modafinil, caffeine, and methylphenidate. It is similar to the stimulation experienced on racemic or the levorotorary form of amphetamine or the racemic methamphetamine, encouraging physical activities such as dancing, socializing, running, or cleaning. The particular style of stimulation which propylhexedrine presents can be described as forced or pressing and is noticeably more adrenergic and tense on the body. This means that at higher dosages, it becomes difficult or impossible to keep still as jaw clenching, involuntarily bodily shakes and vibrations become present, resulting in extreme shaking of the entire body, unsteadiness of the hands, and a general lack of motor control.

Abnormal heartbeat[citation needed] - Heart palpitations are commonly reported on common to heavy doses of this substance due to its significant peripheral nervous system activity.

Increased heart rate[citation needed] - Due to its pronounced peripheral nervous system activity, propylhexedrine tends to increase heart rate much more drastically than comparable dosages of other stimulants.

Vasoconstriction - Propylhexedrine has been noted by users as being particularly vasoconstrictive in comparison to other stimulants. It has been speculated that this is due to its higher affinity for noradrenaline relative to stimulants such as amphetamine.

Visual effects

As with amphetamine or methamphetamine, the visual effects of propylhexedrine are usually less consistent and are only mildly noticeable at higher dosages. They are somewhat comparable to the visual effects produced by deliriants and are generally more frequent in darker areas.

Suppressions

Double vision - An uncommon effect that only occurs at very high, potentially dangerous or toxic dosages.

Distortions

Drifting - This effect is usually subtle and barely noticeable and only occurs at higher dosages or when combined with cannabis. Commonly this consists of level 1-2 drifting.

Cognitive effects

The cognitive effects of propylhexedrine can be broken down into several components which progressively intensify proportional to dosage. The general head space of propylhexedrine is described by many as one of moderate to extreme mental stimulation, increased focus, and powerful euphoria. It contains a large number of typical stimulant cognitive effects. Although negative side effects are usually mild at low to moderate dosages, they become increasingly likely to manifest themselves with higher amounts or extended usage. This particularly holds true during the offset of the experience.
The most prominent of these cognitive effects generally include:

After effects

The effects which occur during the offset of a stimulant experience generally feel negative and uncomfortable in comparison to the effects which occurred during its peak. This is often referred to as a "comedown" and occurs because of neurotransmitter depletion. Its effects commonly include:

Experience reports

Toxicity and harm potential

The toxicity of recreational propylhexedrine use has not been studied as extensively as that of amphetamine or methamphetamine but it is reasonable to assume that most if not all of the same risks apply.

Tolerance and addiction potential

As with other stimulants, the chronic use of propylhexedrine can be considered extremely addictive with a high potential for abuse and is capable of causing psychological dependence among certain users. When addiction has developed, cravings and withdrawal effects may occur if a person suddenly stops their usage.

Tolerance to the effects of this compound likely occurs in the same general fashion as with amphetamine rapidly develops with prolonged and repeated use.[1][2] This results in users having to administer increasingly large doses to achieve the same effects. After that, it takes about 3 - 7 days for the tolerance to be reduced to half and 1 - 2 weeks to be back at baseline (in the absence of further consumption). Propylhexedrine presents cross-tolerance with all dopaminergicstimulants, meaning that after the consumption of propylhexedrine all stimulants will have a reduced effect.

Like with amphetamine and methamphetamine the evidence on effective treatments for dependence and abuse is limited.[3] In light of this, fluoxetine and imipramine appear to have some limited benefits in treating abuse and addiction[4]

In highly dependent amphetamine and methamphetamine abusers, "when chronic heavy users abruptly discontinue methamphetamine use, many report a time-limited withdrawal syndrome that occurs within 24 hours of their last dose".[5] Withdrawal symptoms in chronic, high-dose users are frequent, occurring in up to 87.6% of cases, and persist for three to four weeks with a marked "crash" phase occurring during the first week.[6] Methamphetamine withdrawal symptoms can include anxiety, drug craving, dysphoric mood, fatigue, increased appetite, increased movement or decreased movement, lack of motivation, sleeplessness or sleepiness, and vivid or lucid dreams.[7] Withdrawal symptoms are associated with the degree of dependence (i.e., the extent of abuse).[8] The mental depression associated with methamphetamine withdrawal lasts longer and is more severe than that of cocaine withdrawal.[9]. It is likely that propylhexedrine abuse is subject to these same outcomes.

Psychosis

Like with the abuse of methamphetamine, propylhexedrine abuse can result in a stimulant-induced psychotic state that may present with a variety of symptoms (e.g., paranoia, hallucinations, delusions), though likely to a lesser degree.[10][11] A review on treatment for amphetamine, dextroamphetamine, and methamphetamine abuse-induced psychosis states that about 5–15% of users fail to recover completely.[11][12] The same review asserts that, based upon at least one trial, antipsychotic medications effectively resolve the symptoms of acute amphetamine psychosis.[11]

Dangerous interactions

Although many psychoactive substances are safe to use on their own, they can quickly become dangerous or even life-threatening when combined with other substances. The following lists some known dangerous combinations, but may not include all of them. A combination that appears to be safe in low doses can still increase the risk of injury or death. Independent research should always be conducted to ensure that a combination of two or more substances is safe to consume.

Alcohol - Alcohol can be dangerous to combine with stimulants due to the risk of accidental over-intoxication. Stimulants mask the sedative effects of alcohol, which is the main factor people use to assess their degree of intoxication. Once the stimulant wears off, the depressant effects of alcohol are left unopposed, which can result in blackouts and respiratory depression. If combined, one should strictly limit themselves to only drinking a certain amount of alcohol per hour.

DXM - Combinations with DXM should be strictly avoided due to DXM's effects on serotonin and dopamine reuptake. This can lead to panic attacks, hypertensive crisis, or serotonin syndrome.

MXE - Combinations with MXE may dangerously elevate blood pressure and increase the risk of psychosis.

Tramadol - Tramadol lowers the seizure threshold.[14] Combinations with stimulants may further increase this risk.

MDMA - Like with amphetamines, the neurotoxic effects of MDMA may be increased when combined with propylhexedrine.

Legal status

As such, it may contain incomplete or wrong information. You can help by expanding it.

United States - Propylhexedrine is a legal OTC drug. It is designed not to be recreationally used unless the user decides to bypass the manufacturer's intended design with which it was granted approval to market as a nasal decongestant. The simple consumption of this substance is not technically considered illegal.